Something doesn't smell right with the various post-decision analyses of Roberts' decision. Roberts isn't stupid, yet most of the rationales offered up sure seem to be based on him being so.

Some claims have him wanting to maintain some limit on the federal government's power under the Commerce Clause. First, he didn't need to vote 'yes' on the tax issue to do so, there were already four votes to do so, and Roberts would have made five. He would have had his desired limit. It wasn't as if Kennedy was going to change his mind if Roberts didn't vote 'yes' on the tax issue. And Roberts had to have seen Ginsburg's opinion that made it clear that the liberals were not quietly acquiescing that such mandates were improper.

Second, as has been pointed out, there's no effective limit on the federal government's behavior if Congress can simply impose a 'tax' on anyone not engaging in the desired behavior. Roberts is too smart to not have realized that... and if he wasn't, someone - whether one of his clerks or one of the conservative justices - would have made that point for him.

Others claim that he acted to 'protect the Court from assault'. What assault? From p***ed off liberals? When in the past has Roberts ever indicated that he was concerned about what the editorial pages thought of him (note: Roberts wasn't all that bent out of shape when the Washington Post criticized him in the 'Metro french fry' case. In fact, he stood proudly behind that vote). And what kind of assault would he have been worried about that he would have also thought he could repel with his vote? Roberts wasn't born yesterday, he surely knows that caving in one day doesn't immunize you against attacks tomorrow, that on the contrary, caving in makes more attacks even more likely in the future. Voting to uphold Obamacare wouldn't have given him any room to make a future 'anti-left' decision.

Or what about claims that he wanted to improving the Court's reputation? I don't think so, at least not by coming up with something as convoluted as this. Again, Roberts is not dumb, this isn't his first trip to the decision writing rodeo, there's no way Roberts could ever have thought that this decision would be viewed as great legal reasoning.

Maybe he switched votes so that the court wouldn't be seen as political by overturning Obamacare? Again, this doesn't make sense, I just don't see him thinking anything but the contrary, that switching would be viewed as the political move.

The same logic holds for his wanting to protect his reputation. He had to have known that voting the way he did would kill his reputation on the right. Nor would have helped his reputation on the left, as he knows the left doesn't actually respect so-called conservatives who change their stripes. On the contrary, they're viewed as malleable and without conviction.

A further nail in these theories is that in order for him to accomplish any of these goals, his wavering would have to have remained a secret, and it makes no sense that he could or would have ever thought that. As much as the justices don't like to think it happens, there are leaks of confidential discussions. He had to have known word would get out (as it did)... and when (when, not if) it did, rather than protecting the court's reputation, he would have harmed it.

I really have no clue as what led him to do this, but I'm sure it isn't something that requires him to be that stupid.

Who knows, maybe his family was threatened, the kind of stuff that can make even a tough guy like Harrison Ford back down? A gun to the head of a loved one can make someone do all sorts of things they otherwise wouldn't do.

Maybe he's a closeted gay and he was being blackmailed? (and he gave in, even knowing that he would never be free of the threat?)

Maybe he's broke and took a bribe?

Maybe, figuring that Kennedy would be the 5th vote to support the mandate, Roberts bet heavily on that... only to be caught by surprise when Kennedy announced that he was a no vote?

I am not saying that any of the above is what is happened. But just as they are (hopefully) ludicrous to contemplate, so too are explanations that require Roberts to be dumb, dumb, dumb.